. A textbook on electric lighting and railways. International correspondence schools, Scranton, Pa. v. 1-3, 5 . adjusted for. As a rule, compound-wounddynamos have a shunt in multiple with their series field,as already explained. If this shunt works loose, the greaterpart of the current will flow through the series field and thedynamo will overcompound more than it should. On theother hand, if a series-field connection becomes loose or theshunt short-circuited, the series field will be weakened and 36 ELECTRIC RAILWAYS. :i() the dynamo will fail to overcompound as much as it much th
. A textbook on electric lighting and railways. International correspondence schools, Scranton, Pa. v. 1-3, 5 . adjusted for. As a rule, compound-wounddynamos have a shunt in multiple with their series field,as already explained. If this shunt works loose, the greaterpart of the current will flow through the series field and thedynamo will overcompound more than it should. On theother hand, if a series-field connection becomes loose or theshunt short-circuited, the series field will be weakened and 36 ELECTRIC RAILWAYS. :i() the dynamo will fail to overcompound as much as it much the dynamo will overcompound depends on th^relative resistances of the series-field coils and the series-fieldshunt with which they are in multiple. Any change in thisrelation also changes the degree to which the dynamo willovercompound. 43. Connections fov Compound-Wound Generator. Fig. 15 is a sketch of the connections of an ordinary four-pole railway generator. The machine indicated in Fig. 15has four poles and four brush holders, but it has only twoarmature terminals, because alternate brush holders are. connected together by means of a half circle copper the machine had eight or ten poles and eight or ten brushholders, it would still have only two armature terminals,because all brushes of the same polarity would be joinedtogether. It will be noticed that each field coil is divided into twosections—a thin section next to the frame and a thick sec-tion next to the armature. One section is the fine-wireshunt field and the other section is the series field, which isusually wound with copper strip. The two sections are notonly carefully insulated from the frame of the dynamo, butare insulated from each other. They are put on the spool §20 37 al(>n_i;si(l( of each oilier, so that in case of trouble in one sec-tion, it can be takt-n off withoni disturbin;,;- the otlier the shunt coils aic placed next the yoke and theseries coils
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectelectri, bookyear1901
